# fputc, putc

From cppreference.com
< c‎ | io

Defined in header ``<stdio.h>`` |  |
int fputc( int ch, FILE* stream ); |  |
int putc( int ch, FILE* stream ); |  |

Writes a character ch to the given output stream stream. putc() may be implemented as a macro and evaluate stream more than once, so the corresponding argument should never be an expression with side effects.

Internally, the character is converted to unsigned char just before being written.

### Parameters

ch | - | character to be written
stream | - | output stream

### Return value

On success, returns the written character.

On failure, returns EOF and sets the error indicator (see ferror()) on `stream`.

### Example

Shows `putc` with error checking

Run this code

    #include <stdio.h>
    #include <stdlib.h>

    int main(void)
    {
        int ret_code = 0;
        for (char c = 'a'; (ret_code != EOF) && (c != 'z'); c++)
            ret_code = putc(c, stdout);

        // Test whether EOF was reached.
        if (ret_code == EOF && ferror(stdout))
        {
            perror("putc()");
            fprintf(stderr, "putc() failed in file %s at line # %d\n",
                    __FILE__, __LINE__ - 7);
            exit(EXIT_FAILURE);
        }
        putc('\n', stdout);

        return EXIT_SUCCESS;
    }

Output:

    abcdefghijklmnopqrstuvwxy

### References

- C23 standard (ISO/IEC 9899:2024):

  - 7.21.7.3 The fputc function (p: TBD)

  - 7.21.7.7 The putc function (p: TBD)

- C17 standard (ISO/IEC 9899:2018):

  - 7.21.7.3 The fputc function (p: TBD)

  - 7.21.7.7 The putc function (p: TBD)

- C11 standard (ISO/IEC 9899:2011):

  - 7.21.7.3 The fputc function (p: 331)

  - 7.21.7.7 The putc function (p: 333)

- C99 standard (ISO/IEC 9899:1999):

  - 7.19.7.3 The fputc function (p: 297)

  - 7.19.7.8 The putc function (p: 299)

- C89/C90 standard (ISO/IEC 9899:1990):

  - 4.9.7.3 The fputc function

  - 4.9.7.8 The putc function

### See also

putchar | writes a character to stdout (function)
C++ documentation for fputc, putc

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